WO2006003343A1

WO2006003343A1 - Fluid product dispensing device

Info

Publication number: WO2006003343A1
Application number: PCT/FR2005/050454
Authority: WO
Inventors: Antonio Margheritis; Samuel Pruvot; Ludovic Petit; Serge Herry; Christophe Fagot
Original assignee: Valois Sas
Priority date: 2004-06-16
Filing date: 2005-06-16
Publication date: 2006-01-12
Also published as: EP1768789B3; US8016165B2; CN1968758A; FR2871786A1; US20080029544A1; FR2871786B1; DE602005004152T3; EP1768789A1; EP1768789B1; JP2008502469A; DE602005004152T2; JP5049778B2; DE602005004152D1; CN100434193C

Abstract

The invention concerns a fluid product dispensing device, comprising a reservoir (10), a dispensing head (20) incorporating a dispensing orifice (21), a metering chamber (30) and a plunger (40) sliding in said metering chamber (30) between an inactive position and a dispensing position, said plunger (40) being mounted fixedly in said reservoir (10), said plunger being formed integral with said reservoir (10) and/or with fixing means (100) adapted to be fixed on said reservoir (10).

Description

Fluid dispensing device

The present invention relates to a fluid dispenser device. Fluid dispensing devices generally comprise a reservoir containing the fluid product (liquid, paste or powder) to be dispensed, and a dispensing member mounted on said reservoir, such as a pump or a valve, for selectively dispensing the contents of said fluid. tank. A dispensing head is assembled on the dispensing member to actuate it, in order to manually dispense a dose of product each actuation. When the dispensing member is a pump, this pump generally comprises a pump body defining a pump chamber in which a piston slides between a rest position and a dispensing position. The piston is moved from its rest position to its dispensing position by a pressure exerted by the user on the dispensing head.

The metering chamber may comprise an inlet valve and an outlet valve, and the device may comprise a shutter at its dispensing orifice, generally provided in the dispensing head. In a conventional manner, the pump body is generally fixed to the tank, in any known manner, for example by means of a fixing ring. The piston is then slidably mounted inside said pump body and is displaced by said dispensing head. This implementation has a number of disadvantages. Thus, the sliding surface of the piston in the pump body must be perfectly smooth and regular to prevent a malfunction of this pump, such as a loss of seal, or a blockage of the piston. This imposes very important precautions when assembling the pump body on the tank, to prevent this pump body is deformed during this assembly. In particular, a number of assembly methods are very difficult to achieve when it is desired to fix a pump body on a tank neck. This is particularly true when it comes to snapping inside the neck, since if the neck is rigid, it is generally necessary to be able to deform the snapped portion, namely the pump body, which generates a risk of deformation of the sliding surface of the piston with the aforementioned drawbacks.

Another disadvantage of conventional pumps is that the metering chamber is generally arranged relatively far from the dispensing orifice, and it is then necessary to provide both an outlet valve of the metering chamber to ensure an accurate definition of the metering chamber. this dosage, and a shutter at the dispensing orifice to avoid any risk of contamination of the product between two actuations. In addition, this generally involves the use of two springs, one to return the piston to its rest position, and the other to bias the shutter to its closed position.

Furthermore, another disadvantage of existing pumps is related to the assembly which provides for fixing a pump (or some pump elements) to a tank by means of a fixing ring or the like. When the pump portion to be fixed is the pump body, the assembly thereof on the tank by means of a fixing ring does not pose a major problem, but still requires two separate steps of assembly (pre -assembling the pump body in the ring or on the tank, then fixing the ring). When the pump element to be assembled on the reservoir is an internal part of the pump, this assembly can also be more difficult and may damage sealing parts of said element. It follows a generally complex pump to manufacture and assemble, which can be detrimental from the point of view of the performance of the pump and its cost.

The present is intended to provide a fluid dispensing device that does not reproduce the aforementioned drawbacks.

More particularly, the present invention aims to provide such a fluid dispensing device which eliminates any risk of alteration of the sliding surface of the piston during assembly of the device.

The present invention also aims to provide such a fluid dispensing device which comprises a minimum of component parts.

In particular, the invention eliminates one, respectively two pieces (s) assembly by realizing the one-piece piston with the fixing means, respectively the reservoir. In addition, the invention eliminates the need to accumulate an outlet valve of the metering chamber and a shutter of the dispensing orifice, and allows for a shutter pump having only one spring.

The present invention also aims to provide such a fluid dispenser device that is simple and inexpensive to manufacture and assemble, safe and reliable operation, and avoids any risk of contamination of the product contained in said device. The present invention therefore relates to a fluid dispenser device comprising a reservoir, a dispensing head incorporating a dispensing orifice, a metering chamber and a piston sliding in said metering chamber between a rest position and a position. distribution, said piston being fixedly mounted on said reservoir, said piston being made integrally with said reservoir and / or with fixing means adapted to be fixed on said reservoir.

Advantageously, said piston is fixed on the reservoir by fixing means, said fixing means being integrally connected to said piston. Advantageously, said fixing means are latching means, fitting or screwing.

According to a first embodiment, said piston is attached to the outside of a neck of said tank.

According to a second embodiment, said piston is fixed inside a neck of said tank.

According to a third embodiment, said piston is fixed to the outside and inside of a neck of said tank.

According to a fourth embodiment, said piston is made integrally with said reservoir. Advantageously, said piston slides in a pump body disposed in the dispensing head. Advantageously, said pump body is integral with a shutter sliding in said dispensing head between a closed position and an open position of the dispensing orifice.

Advantageously, said shutter comprises a second piston sliding in a cylinder of said dispensing head.

Advantageously, said piston comprises an inlet valve of the pump chamber.

Advantageously, said piston is fixed on the reservoir with interposition of a seal between the piston and the reservoir. Advantageously, said seal is deformed during attachment of said piston to said reservoir.

Advantageously, the piston comprises fastening means cooperating with the outside of a neck of the reservoir, said seal cooperating with the interior of said neck. Alternatively, the piston comprises fastening means cooperating with the interior of a tank neck.

Advantageously, said fixing means comprise said seal which is deformed between the piston and the inside of the neck of the reservoir to fix the piston by press fitting into said neck. Advantageously, one of the inner surface of the neck of the reservoir and the corresponding outer surface of the piston comprises a sealing profile cooperating with said seal in the mounted state, preferably with a complementary sealing profile of said seal.

Advantageously, said seal comprises a projection which, during the fitting of the piston, is deformed under the neck of the reservoir, inside thereof, to fix the piston indemountably.

Advantageously, said piston comprises latching means cooperating with the inner surface and / or the outer surface of a neck of said tank. Advantageously, said latching means comprise a snap-fitting profile adapted to snap into respectively around said neck. Advantageously, said neck comprises a complementary snap profile cooperating with said detent profile of said piston.

Advantageously, the piston comprises a thread cooperating with a corresponding thread provided inside or outside a neck of said reservoir. Advantageously, at least one of said threads comprises means preventing unscrewing, such as an interrupted thread.

Advantageously, said piston comprises first latching means co-operating with the inside of a neck of the reservoir and second latching means co-operating with the outside of said neck. Advantageously, the inside and / or outside of said neck comprises a complementary snap profile.

Advantageously, the upper edge of a neck of the reservoir comprises two axial branches each cooperating with said piston, preferably with the interposition of a seal. Advantageously, said detent means are formed directly on the piston.

Advantageously, a sleeve is interposed between the piston and a neck of said reservoir.

Advantageously, said latching means are formed on said sleeve.

Advantageously, a seal is interposed between said bushing and the neck of the tank.

Advantageously, said piston is force-fitted directly inside a neck of said reservoir. Other features and advantages of the present invention will emerge more clearly in the following detailed description of several embodiments thereof, with reference to the accompanying drawings, given by way of non-limiting examples, and in which:

- Figures 1 and 2 are schematic cross-sectional views of a fluid dispenser device according to an advantageous embodiment of the present invention, respectively before and after assembly; - Figures 3a and 3b are detail views of an alternative embodiment of the fastening means, respectively before and after assembly;

- Figure 4 is a view similar to Figure 3b, showing another embodiment of the fastening means in the assembled position; FIG. 5 is a diagrammatic view in partial cross section of a fluid dispenser device according to another advantageous embodiment of the invention;

- Figure 6 is a partial cross-sectional view of another alternative embodiment of a fluid dispenser device according to the invention;

FIG. 7 is a view similar to FIG. 5, showing yet another alternative embodiment of the present invention;

- Figure 8 is a view similar to those of Figures 5 and 7, showing yet another alternative embodiment of the present invention; - Figures 9 to 10 show schematic cross-sectional views of a fluid dispensing device produced according to yet another embodiment of the invention, respectively before and after assembly;

FIGS. 11a and 11b are enlarged diagrammatic cross-sectional views of details A and B of FIGS. 9 and 10;

FIGS. 12a and 12b are views similar to those of FIGS. 11a and 11b, showing an alternative embodiment of the present invention;

- Figures 13a and 13b are views similar to Figures 12a and 12b, showing another embodiment of the invention; - Figures 14 and 15 are schematic cross-sectional views of a fluid dispenser device according to yet another embodiment of the present invention, respectively before and after assembly;

Figures 16 and 17 are diagrammatic cross-sectional views of details C and D of Figures 14 and 15; - Figures 18 and 19 are views similar to Figures 16 and 17 showing alternative embodiments of the invention; Fig. 20 is a schematic cross-sectional view of a fluid dispenser according to yet another embodiment of the present invention;

Fig. 21 is a view similar to that of Fig. 20 showing also yet another embodiment of the present invention;

Fig. 22 is a schematic cross-sectional view of the detail E of Fig. 20;

- Figure 23 is a view similar to that of Figure 22 showing an alternative embodiment of the present invention; and FIG. 24 is a partial schematic cross-sectional view of yet another variant of the fastening means according to the present invention.

This invention relates to a fluid dispenser device comprising a reservoir 10 containing a fluid product, for example a cosmetic pharmaceutical product or the field of perfumery. This reservoir 10 preferably comprises a neck 11 defining an opening for the insertion and attachment of a dispensing member, such as a pump, as will be described below. A dispensing head 20 is movably assembled relative to the reservoir 10, this head 20 having a dispensing orifice 21 through which the product is dispensed at each actuation. A metering chamber 30 is further defined in which a piston slides

40 between a rest position and a dispensing position. The metering chamber for precisely defining the amount of product dispensed with each actuation, the displacement of said piston 40 causing the expulsion of a dose of product. According to the invention, said piston 40 is fixedly mounted on said reservoir 10 by being integrally formed either directly with the reservoir, or with fixing means adapted to be fixed on said reservoir. It is thus possible to save at least one constituent part compared to existing assemblies. The various figures represent several embodiments and variants of the invention. Thus, in FIG. 21, said piston 40 is made integrally with said reservoir 10, and in this case the product can be introduced into the tank by the bottom thereof, a suitable plug being then fixed in any way to seal the tank. In the other figures, the piston 40 is fixed on the reservoir by fastening means 100. These various fastening means will be described below with reference to the various figures which represent different embodiments.

The various figures represent a particular fluid product distribution device, but it is understood that the present invention is not limited to the features shown, in particular with regard to the parts of the device which do not form the fixing means 100 of the piston 40 on the reservoir 10. Thus, the shape of the dispensing head 20 can be any and the orifice 21 is not necessarily axial. Similarly, in the examples shown, the piston 40 slides in a cylinder 50 forming a pump body inside which the metering chamber 30 is defined. This pump body 50 is advantageously made in one piece with a shutter 55 arranged in upstream of the dispensing orifice 21. Furthermore, the pump body 50 comprises a second piston 58 adapted to slide in a cylinder 28 of the dispensing head 20. A return spring 80 urges said shutter 55 towards its closed position of the dispensing orifice 21, and during actuation, said shutter can slide towards an opening position of the dispensing orifice 21, under the effect of the pressure of the product, which displaces said second piston 58 in the cylinder 28 against the force of the return spring to open the dispensing orifice and allow the expulsion of the dose of product contained in the metering chamber 30. Indeed, during the displacement of the shutter 55, the piston 40 slides in the body 50 to dispense the dose. Advantageously, an inlet valve 45 is provided upstream of the metering chamber 30, and this inlet valve can advantageously be formed on said piston 40. In the example shown, the valve seat is formed on the piston 40 and the valve member is a ball 45. Of course, any other form of inlet valve is conceivable. A dip tube 90 can be assembled in the piston 40 to allow the expulsion of all the product contained in the reservoir

10. Advantageously, the cylinder 28 of the dispensing head 20 extends to the inside of the neck 11 of the reservoir 10 when the device is in the actuating or dispensing position, in order to improve the stability of the assembly and to reduce the overall dimensions of the device. To ensure stability and simple and easy attachment of the piston 40 to the reservoir 10, the piston 40 advantageously comprises, at the end opposite the sealing portion 41 forming the piston itself and which slides in the pump body 50, a radial flange 42 intended to rest on the upper edge of the neck 11 of the tank 10, said flange 42 extending through an axial well 43 penetrating inside the neck 11 of the tank 10, and which connects to a tubular portion 44 also axial having at its upper end (in the direction shown in the figures) said sealing portion 41 forming a piston. This tubular element 44 advantageously comprises a shoulder 46 adapted to receive the end of the return spring 80 opposite the second piston 58 of the pump body 50. This tubular element 44 is hollow and connects the dip tube 90 to the inlet valve 45 and therefore to the metering chamber 30. Advantageously, the dispensing head 20 is further snapped onto the piston 40 or the neck 11 of the reservoir 10, or on any element integral with one of these two elements, in order to avoid any risk of unwanted or accidental disassembly of said head 20 with respect to said tank 10. As explained above, these different characteristics are only shown by way of examples, and different variants not shown could also be envisaged.

According to a first embodiment of the invention, represented in FIG. 21, the piston 40 is thus made in one piece with the reservoir 10. According to another embodiment of the invention, the piston 40 is fixed to the outside the neck 11 of the tank. Figures 1 to 4 show such snap fastening. For this purpose, latching means forming a snap-fastening profile 120 cooperating with the outside of the neck 11 are provided, preferably made in one piece with the piston 40. Advantageously, the neck 11 may comprise a complementary snap profile 16 intended to to cooperate with the latching profile 120 of the latching means. Preferably, a seal 60 is interposed between the piston 40 and the neck 11 of the reservoir. Preferably, as shown in Figures 1 to 4, this seal is deformed during attachment of the piston 40 on the reservoir 10, which promotes a good seal at this location.

FIGS. 3a and 3b show an alternative embodiment of the seal 60, which comprises a sealing profile 61 adapted to cooperate with a complementary sealing profile 70 provided on the outer surface of the axial well 43 of the piston 40 which extends to inside the neck 11 of the tank. In the example shown, this complementary latching profile 70 is designed as a projection which for example cooperates with two flexible tabs 61 of the gasket 60, which are crushed against the said projection when the piston 40 is fastened to the piston. tank 10.

FIG. 4 shows an alternative embodiment in which the detent profile 70 is formed on the inner surface of the neck 11 of the reservoir, in which case the seal 60 advantageously also has a complementary snap profile 61 but disposed on the opposite side with respect to to the variant shown with reference to Figures 3a and 3b. Of course, as an alternative to snapping, one could also imagine an attachment outside the neck 11 of the tank by means of a thread or crimping.

According to another alternative embodiment of the invention, the piston is fixed inside the neck 11 of the tank 10. FIG. 5 shows an embodiment in which the axial shaft 43 of the piston 40 is directly fitted with force to the inside the neck 11 of the tank. Fixing and sealing are obtained by this force fitting, which can be particularly solid since the fitted portion no longer forms the pump body in which the piston of the pump must slide. This can therefore be deformed as much as necessary during fitting to position itself securely inside the neck of the tank.

Figure 6 shows an alternative embodiment in which a thread 80 is provided on the piston 40, in particular on the axial shaft 43, and which cooperates with a corresponding thread 85 provided inside the neck 11 of the reservoir.

Advantageously, a seal 60 is interposed between the piston 40 and the upper edge of the reservoir 10, and means preventing unscrewing can be provided, for example example made in the form of a thread interrupted on one or the other of said threads 80, 85.

FIGS. 7 and 8 show two alternative embodiments of a snap-fastening inside the neck 11 of the tank 10. In these two cases, the piston 40, in particular the axial well 43, comprises snap-fastening means comprising a profile of FIG. snap 110 adapted to cooperate with the neck 11 of the tank. Advantageously, a complementary snap profile 15 can be provided inside said neck 11. Again, such a snap is made possible because the piston 40, at its portion which is fixed on the neck 11 of the reservoir 10 , does not define a sliding surface that can be irreversibly deformed during attachment, and that could affect the proper functioning of the device. On the contrary, the structure shown and described above of the piston 40 allows inward deformation thereof, and thus easy snap-fitting inside the neck 11 of the tank. Again, a seal 60 can be interposed between the piston 40 and the reservoir 10.

Figures 9 to 13b show other embodiments. In these examples, a seal 60 is interposed between the piston 40 and the inner surface of the neck 11 of the reservoir. Figures 9, 10, 11a and 11b show a first embodiment. In this first variant, a sleeve 150 is also interposed between the piston 40 and the neck 11 of the reservoir, this sleeve 150 receiving the seal 60. This seal 60 may include an end extension 65 which is deformed at the very last moment when the assembly of the device, this deformation causing a constraint of the seal 60 and therefore a good seal. As shown in Figures 9, 10, 11a and 11b, the sleeve 150 has an upper shoulder and a lower shoulder between which is disposed the seal 60 in the unstressed state before assembly. During the final phase of the assembly, the upper extension 65 of the seal 60 is deformed, in this case moved axially downwards, which has the effect of an expansion of the seal 60 on the inner surface of the neck 11 of the reservoir . This radial expansion ensures both the sealing and the fixing of the piston 40 in the reservoir 10. Figures 12a and 12b show an alternative embodiment of that described above, wherein the lower shoulder of the sleeve 150 further comprises a snap profile 110 which snaps or connects to the complementary profile 15 provided inside the neck 11 of the tank. Figures 13a and 13b show another alternative embodiment in which there is no socket, but the seal 60 is similar to that described with reference to Figures 3a and 3b. This variant differs from that of Figures 3a and 3b by the absence of latching means outside the neck 11 of the tank. Fixing is here also ensured by the radial clamping of the seal 60 between the neck 11 of the reservoir 10 and the axial well 43 of the piston 40.

Figures 14 to 19 show yet another alternative embodiment. In this variant embodiment, the seal 60 comprises a projection 65 which is adapted to deform during the assembly of the piston 40 so that it is positioned under the neck 11 of the reservoir, inside the latter. ci, to ensure a fixable mounting of the device and improved sealing. FIGS. 16 and 17, which are enlarged views of the details C and D of FIGS. 14 and 15, clearly show how the projection 65, which before assembly is applied against the piston 40, is deformed during assembly by the frustoconical shape of the lower end of the axial well 43 of the piston which cooperates with said projection 65. Figures 18 and 19 show two embodiments respectively before and after assembly, Figure 18 showing a sleeve 150 interposed between the piston 40 and the neck 11 of the reservoir, the seal 60 being interposed between the sleeve 150 and the neck 11. Figure 19 shows it a seal 60 cooperating with a radial flange seal portion made of a different material, which allows to adapt the requirements of sealing and flexibility. All the joints described with reference to FIGS. 9 to 19 are advantageously made by overmoulding, in particular when they are intended to cooperate with a bushing 150 as represented in FIGS. 11a to 13b. In this case, the seal 60 is injected around said sleeve 150, which allows for said upper extension 65 which deforms the seal 60 at the end of assembly. Figs. 20 and 22-24 show another embodiment in which the piston is secured both inside and outside the neck 11 of the reservoir 10. Referring to Figs. 20 and 22, Fig. 22 being an enlarged view of the detail E of FIG. 20, it can be seen that the piston 40 comprises an external snap-fastening profile 120 cooperating with a corresponding profile 16 provided on the outside of the neck 11 of the reservoir, said reservoir neck also comprising bead or other internal profiles on its inner surface adapted to cooperate with the piston 40 to seal. Of course, these profiles could also be provided on the piston 40 rather than in the neck 11 of the tank. Fixing is here carried out by snapping on the outside and fitting inside the neck of the tank.

Figure 23 shows an alternative embodiment in which the piston 40 is fixed on the neck 11 of the tank by snapping both inside and outside thereof. In this case, the piston 40 comprises external and internal snap-fastening profiles 110 which cooperate respectively with corresponding snap-fastening profiles 16 and 15 of the neck of the reservoir 11.

Finally, in the embodiment of FIG. 24, the upper edge of the neck 11 of the reservoir 10 comprises two substantially parallel axial branches 18 and 19 each cooperating with the piston 40, preferably with the interposition of a seal 60. In this case, snapping can be done inside one of the branches

18 while the other branch can support said seal 60. Of course, different fixing and sealing means could be envisaged, with such a complex configuration of the neck of the tank. It should be noted that this internal and external double clipping could also be used to fix a pump body on a tank.

The present invention therefore makes it possible to produce a fluid dispenser device which is simple and easy to assemble, the assembly presenting no risk for the operation of the pump, and in particular not altering in any way the sliding surface of the body. pump 50 or piston 40 itself at its sealing portion 41 sliding in said pump body 80. On the contrary, fixing the piston 40 directly on the reservoir, unlike the conventional device in which it is the pump body which is attached to the tank, allows to achieve such a fixation in different ways very varied, safe simple and reliable. Another advantage of this implementation is to make it possible to produce the metering or pump chamber 30 directly upstream of the dispensing orifice 21, which makes it possible to produce the shutter 55 and the outlet valve of this chamber. dosage 30 as one and the same piece. It is therefore no longer necessary to provide an outlet valve for the metering chamber and, after an expulsion channel extending through the dispensing head, a shutter separated from said valve at the dispensing orifice, as is the case in most existing devices. The present invention therefore makes it possible to produce a pump which is more compact and has fewer parts, and which is therefore less expensive. Similarly, the present invention has only one spring 80 which acts as a return spring of the pump and to close the shutter 55, while in existing devices, when there is a shutter placed directly upstream of the dispensing orifice 21, there are generally two springs, one to urge the shutter towards its closed position and the other to return the piston to its rest position. The present invention therefore again makes it possible to improve and simplify the pumps of the prior art. Of course, the invention has been described with reference to several variants with reference to the drawings, but these are not limiting, and conversely the skilled person can make various modifications without departing from the scope of this invention as defined by the appended claims.

Claims

claims

1.- Fluid dispensing device, comprising a reservoir (10), a dispensing head (20) incorporating a dispensing orifice (21), a metering chamber (30) and a piston (40) sliding in said chamber metering device (30) between a rest position and a dispensing position, said piston (40) being fixedly mounted on said reservoir (10), characterized in that said piston is integrally formed with said reservoir (10) and / or with fixing means (100) adapted to be fixed on said tank (10).

2.- Device according to claim 1, wherein said piston (40) is fixed on the reservoir (10) by fixing means (100), said fixing means (100) being integrally connected to said piston (40) .

3.- Device according to claim 2, wherein said fixing means (100) are latching means, fitting or screwing.

4.- Device according to claim 2 or 3, wherein said piston (40) is attached to the outside of a neck (11) of said reservoir (10).

5.- Device according to claim 2 or 3, wherein said piston (40) is fixed inside a neck (11) of said reservoir (10).

6.- Device according to claim 2 or 3, wherein said piston (40) is fixed to the outside and inside of a neck (11) of said reservoir (10).

7.- Device according to claim 1, wherein said piston (40) is formed integrally with said reservoir (10).

8.- Device according to any one of the preceding claims, wherein said piston (40) slides in a pump body (50) disposed in the dispensing head (20).

9.- Device according to claim 8, wherein said pump body (50) is integral with a shutter (55) sliding in said dispensing head (20) between a closed position and an open position of the dispensing orifice (21).

10.- Device according to claim 9, wherein said shutter

(55) comprises a second piston (58) sliding in a cylinder (28) of said dispensing head (20).

11.- Device according to any one of claims 8 to 10, wherein said piston (40) comprises an inlet valve (45) of the pump chamber (30).

12.- Device according to any one of the preceding claims, wherein said piston (40) is fixed on the reservoir (10) with interposition of a seal (60) between the piston (40) and the reservoir (10).

13.- Device according to claim 12, wherein said seal (60) is deformed during attachment of said piston (40) on said reservoir (10).

14.- Device according to claim 12 or 13, wherein the piston

(40) comprises fastening means (100) cooperating with the outside of a neck (11) of the reservoir (10), said seal (60) cooperating with the interior of said neck (11).

15.- Device according to claim 12 or 13, wherein the piston (40) comprises fastening means (100) cooperating with the interior of a neck (11) of the reservoir (10).

16.- Device according to claim 15, wherein said fixing means (100) comprise said seal (60) which is deformed between the piston (40) and the inside of the neck (11) of the reservoir (10) to fix the piston (40) by press fit into said neck (11).

17.- Device according to claim 14 or 16, wherein one of the inner surface of the neck (11) of the reservoir (10) and the corresponding outer surface of the piston (40) comprises a sealing profile (70) cooperating with said seal (60) in the mounted state, preferably with a complementary sealing profile (61) of said seal (60).

18.- Device according to any one of claims 15 to 17, wherein said seal (60) comprises a projection (65) which, during the fitting of the piston (40), is deformed under the neck (11) of the reservoir (10), inside thereof, to fix the piston (40) in a way that can not be dismantled.

19.- Device according to any one of the preceding claims, wherein said piston (40) comprises latching means (110, 120) cooperating with the inner surface and / or the outer surface of a neck (11) of said tank (10).

20.- Device according to claim 19, wherein said detent means (110, 120) comprise a detent profile (110, 120) adapted to snap into respectively around said neck (11).

21.- Device according to claim 20, wherein said neck (11) comprises a complementary snap profile (15, 16) cooperating with said snap profile (110, 120) of said piston (40).

22. Apparatus according to any preceding claim, wherein the piston (40) has a thread (80) cooperating with a corresponding thread (85) provided inside or outside a neck (11). ) of said reservoir (10).

23.- Device according to claim 22, wherein at least one of said threads (80, 85) comprises means preventing unscrewing, such as a thread interrupted.

24.- Device according to any one of the preceding claims, wherein said piston (40) comprises first latching means

(110) cooperating with the inside of a neck (11) of the tank (10) and second latching means (120) cooperating with the outside of said neck

(11).

25.- Device according to claim 24, wherein the inside and / or outside of said neck (11) has a complementary snap profile (15, 16).

26.- Device according to any one of the preceding claims, wherein the upper edge of a neck (11) of the reservoir (10) comprises two axial branches (18, 19) each cooperating with said piston (40), preferably with interposition of a seal (60).

27.- Device according to claim 20 or 21, wherein said latching means (110, 120) are formed directly on the piston.

28.- Device according to any one of the preceding claims, wherein a sleeve (150) is interposed between the piston (40) and a neck (11) of said reservoir (10).

Apparatus according to claim 28 and one of claims 20 and 21, wherein said detent means (110) is formed on said bushing (150).

30.- Device according to claim 28 or 29, wherein a seal (60) is interposed between said sleeve (150) and the neck (11) of the reservoir (10).

31.- Device according to any one of the preceding claims, wherein said piston (40) is forced-fitted directly inside a neck (11) of said reservoir (10).